His first assignment was to the support crew for the Soyuz 21 flight. This was the first flight to Salyut 5. The crew were on board for 50 days but began to experience problems towards the end of the mission due to psychological problems. There was also some suspicsion that there was toxins in the station atmosphere.

He the moved to the backup crew for Soyuz 23. This was meant to dock with Salyut 5 but the rendezvous system failed. The capsule landed in Lake Tengiz, in a -20°C temperatures during a snowstorm. The capsule was dragged under the surface and the heating system had to be turned off to conserve the battery power. It was not until the next morning that they could be recovered, miracously still alive.

It was found that there was no toxins in the air but they carried out the operation anyway. This meant that a planned EVA was not performed. The mission at only 18 days but was classed as highly successful, accomplishing nearly as much as the earlier Soyuz 21's 50 day mission.

Glazkov spennt 17 days 17 hours and 25 minutes in space.

He was also to have been on the prime crews for first TKS flights. TKS was a manned spacecraft designed for the military space stations so that they could operate autonomously from the whims of the Soyuz spacecraft manufacturer. The program was cancelled after problems were encountered on the test flights and the rising costs associated.